Atorvastatin is a reductase inhibitor of the enzyme 3-hydroxy-3-methylglutarate-coenzyme A (HMG-CoA) and therefore is a useful anti-hyperlipoproteinemic agent. It has proven to be a highly effective medicament for the treatment of disorders such as hyperlipidemia and hypercholesterolemia which are conditions that are known risk factors for arteriosclerosis and coronary heart disease. Atorvastatin is chemically [R-(R*,R*)]-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-(phenylcarbamoyl)-1H-pyrrole-1-heptanoic acid and is marketed as its calcium salt in a 2:1 molar ratio between the atorvastatin and the calcium (designated herein as atorvastatin hemicalcium salt) under the brand name Lipitor™.